Low noise biodegradable breathable films

Abstract

The present invention relates to a breathable film comprising at least one biodegradable polymer, a process for producing the breathable film, the use of a surface-treated filler material product as filler in the breathable film, an article comprising the breathable film as well as the use of the breathable film in hygienic applications, medical applications, healthcare applications, filtration materials, geotextile products, agricultural applications, horticultural applications, clothing, footwear products, baggage products, household applications, industrial applications, packaging applications, building applications, or construction.

1 .- 16 . (canceled) 
     
     
         17 . A breathable film comprising at least one biodegradable polymer and from 35 to 65 wt.-%, based on the total weight of the breathable film, of a surface-treated filler material product, wherein the surface-treated filler material product comprises
 A) at least one ground calcium carbonate-comprising filler material having
 a weight median particle size d 50  in the range from 0.1 μm to 7 μm, 
 a top cut particle size d 98  of ≤15 μm, 
 a specific surface area (BET) from 0.5 to 150 m 2 /g, as measured using nitrogen and the BET method according to ISO 9277, and 
 a residual total moisture content in the range from 0.05 to 0.3 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material 
   B) a treatment layer on the surface of the at least one ground calcium carbonate-comprising filler material comprising
 i. at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salts thereof, and/or 
 ii. at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof, 
   wherein the surface-treated filler material product comprises the treatment layer in an amount of from 0.1 to 3 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material, and   wherein the at least one biodegradable polymer has a tensile E-modulus, measured according to ISO 527-3, of below 2100 MPa.   
     
     
         18 . The breathable film of  claim 17 , wherein the at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof comprises at least one aliphatic carboxylic acid having a total amount of carbon atoms from C4 to C24 and/or a salt thereof. 
     
     
         19 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material is a wet ground calcium carbonate-comprising filler material. 
     
     
         20 . The breathable film of  claim 17 , wherein the at least one biodegradable polymer is selected from the group consisting of polylactic acid, polylactic acid-based polymer, polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), poly-3-hydroxybutyrate (P3HB), polyhydroxyvalerate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polybutyrate-adipate-terephthalate (PBAT), polyglyconate, poly(dioxanone), polybutylene succinate (PBS), polycaprolactone (PCL), polycaprolactone-poly(ethylene glycol) copolymer, polycaprolactone-polylactic acid copolymer, polyvinylalcohol (PVA), poly(ethylene succinate) (PES), poly(propylene succinate) (PPS), and mixtures thereof. 
     
     
         21 . The breathable film of  claim 17 , wherein the at least one biodegradable polymer is selected from the group consisting of polylactic acid, polylactic acid-based polymer, polybutyrate-adipate-terephthalate (PBAT), and mixtures thereof. 
     
     
         22 . The breathable film of  claim 17 , wherein the at least one biodegradable polymer is a blend of polybutyrate-adipate-terephthalate (PBAT) and polylactic acid. 
     
     
         23 . The breathable film of  claim 17 , wherein the at least one biodegradable polymer is a blend of polybutyrate-adipate-terephthalate (PBAT) and polylactic acid with a weight ratio ranging from 10:1 to 1:9. 
     
     
         24 . The breathable film of  claim 17 , wherein the breathable film comprises the surface-treated filler material product in an amount from 40 to 65 wt.-%, based on the total weight of the breathable film. 
     
     
         25 . The breathable film of  claim 17 , wherein the breathable film comprises the surface-treated filler material product in an amount from 40 to 60 wt.-%, based on the total weight of the breathable film. 
     
     
         26 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material is natural ground calcium carbonate, precipitated calcium carbonate, modified calcium carbonate, surface-treated calcium carbonate, or a mixture thereof. 
     
     
         27 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material is natural ground calcium carbonate. 
     
     
         28 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material has
 a) a weight median particle size d 50  from 0.25 μm to 5 μm, and/or   b) a top cut particle size d 98  of ≤12.5 μm, and/or   c) a fineness such that at least 5 wt.-% of all particles have a particle size of <0.5 μm, and/or   d) a specific surface area (BET) of from 0.5 to 50 m 2 /g, as measured using nitrogen and the BET method according to ISO 9277.   
     
     
         29 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material has
 a) a weight median particle size d 50  from 0.6 μm to 2 μm, and/or   b) a top cut particle size d 98  of ≤6.5 μm, and/or   c) a fineness such that at least 9 wt.-% of all particles have a particle size of <0.5 μm, and/or   d) a specific surface area (BET) of from 0.5 to 15 m 2 /g, as measured using nitrogen and the BET method according to ISO 9277.   
     
     
         30 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material has a fineness such that at least 11 wt.-% of all particles have a particle size of <0.5 μm. 
     
     
         31 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material has a residual total moisture content of from 0.05 to 0.2 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material. 
     
     
         32 . The breathable film of  claim 17 , wherein the at least one ground calcium carbonate-comprising filler material has a residual total moisture content of from 0.05 to 0.12 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material. 
     
     
         33 . The breathable film of  claim 17 , wherein the treatment layer on the surface of the at least one ground calcium carbonate-comprising filler material comprises at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C4 to C18 in the substituent and/or salts thereof. 
     
     
         34 . The breathable film of  claim 17 , wherein the surface-treated filler material product has a moisture pick-up from 0.1 to 1 mg/g, at a temperature of 23° C. (±2° C.). 
     
     
         35 . The breathable film of  claim 17 , wherein the surface-treated filler material product has a moisture pick-up from 0.2 to 0.8 mg/g, at a temperature of 23° C. (±2° C.). 
     
     
         36 . The breathable film of  claim 17 , wherein the film has a basis weight from 8 to 40 g/m 2 . 
     
     
         37 . The breathable film of  claim 17 , wherein the film has a basis weight from 20 to 36 g/m 2 . 
     
     
         38 . A process for producing a breathable film comprising at least one biodegradable polymer and from 35 to 65 wt.-%, based on the total weight of the breathable film, of a surface-treated filler material product, the process comprising the steps of:
 a) providing a composition comprising at least one biodegradable polymer band from 35 to 65 wt.-%, based on the total weight of the composition, of a surface-treated filler material product, wherein the at least one biodegradable polymer has a tensile E-modulus, measured according to ISO 527-3, of below 2100 MPa, and   b) forming a film from the composition of step a), and   c) stretching the film obtained in step b) into at least one direction,   
       wherein the surface-treated filler material product comprises
  A) at least one ground calcium carbonate-comprising filler material having
 a weight median particle size d 50  in the range from 0.1 μm to 7 μm, 
 a top cut particle size d 98  of ≤15 μm, 
 a specific surface area (BET) from 0.5 to 150 m 2 /g, as measured using nitrogen and the BET method according to ISO 9277, and 
 a residual total moisture content in the range from 0.05 to 0.3 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material, and 
 
 B) a treatment layer on the surface of the at least one ground calcium carbonate-comprising filler material comprising
 i. at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salts thereof, and/or 
 ii. at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof, 
 
 wherein the surface-treated filler material product comprises the treatment layer in an amount of from 0.1 to 3 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material. 
 
     
     
         39 . The process of  claim 38 , wherein the at least one saturated or unsaturated aliphatic linear or branched carboxylic acid and/or salts thereof comprises at least one aliphatic carboxylic acid having a total amount of carbon atoms from C4 to C24 and/or a salt thereof. 
     
     
         40 . The process of  claim 38 , wherein the composition provided in step a) is a masterbatch or a compound obtained by mixing and/or kneading the at least one biodegradable polymer and the surface-treated filler material product to form a mixture and continuously pelletizing the obtained mixture. 
     
     
         41 . An article comprising a breathable film comprising at least one biodegradable polymer and from 35 to 65 wt.-%, based on the total weight of the breathable film, of a surface-treated filler material product according to claim  1 , wherein the article is selected from the group consisting of hygiene products, medical products, healthcare products, filter products, geotextile products, agriculture products, horticulture products, clothing, footwear products, baggage products, household products, industrial products, packaging products, building products, and construction products.